Strike-off mechanism for molding machines



Nov. 19, 1929. J. T. RAMSDEN 1,736,365

7 STRIKE-OFF MECHANISM FOR MOLDING MACHINES Filed May 22, 1928 1 2 Sheets-Sheet 1 [A l (#701? Q (J 6)? reifavzso c n W mshu ixg Nov. 19, 1929.

J. T. RAMSDEN- STRIKE-OFF MECHANISM FOR MOLDING MACHINES Filed May 22, 1928 2 Shets-Sheet wwwrw? (70/971 7 ffimsc/en er Afro/Mix Patented Nov. 19, 1929 UNITED STATES PATENT OFFIQE JOHN T. RAMSDEN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE TABOR MANUFACTURING COMPANY, A CORPORATION PEN'NSYLYA NI A STRIKE-OFF MECHANISM FOR MOLDING MACHINES Application filed May 22,

The principal object of the present invention is to provide comparatively simple, reliable and eflicient means for automatically striking surplus sand off the flask in advance of the movement of the ramming yoke or head into vertical position and for clearing the flask by the movement of said yoke or head, and in a similar manner to carry the strikeofl' mechanism back and clear of the flask when the ramming head or yoke is turned back into inclined position. Another object of the invention is to provide comparatively simple, reliable and efiicient means for causing the strike-off bar to travel across and clear of the flask and in a substantially straight line in response to swinging movement of the head or yoke.

Generally stated, the invention comprises a molding machine having a frame and a 2 hinged yoke or ramming head swingable over a flask and back of the same, arms pivoted intermediate of their lengths to the yoke and having at one of their ends a strike-off bar,

a fulcrum fixed in respect to the frame and eccentric in respect to the hinge of the yoke,

and links interposed between the fixed fulcrum and the other ends of the arms.

The invention also comprises the improve ments to be presently described and finally claimed.

In the following description reference will be made to the accompanying drawings forming part hereof and illustrating an embodiment of the invention and in which Figure l is a front view showing a molding machine provided with a swinging yoke or head and with a frame in respect to which the yoke swings and embodying features of the invention, and V Fig. 2 is a side view partly in section drawn to an enlarged scale and showing by full lines one position and by dotted lines another position of mechanism embodying features of the invention and also parts of the machine with which that mechanism cooperates.

Referring to the drawings 1 is a yoke swingable about the hinge 2, carried by the frame 8, into vertical position over the flask at and into inclined position clear of the flask 4. In

many instances the parts are duplicated on 1928. Serial No. 279,794.

each side of the machine so. that for the sake of clearness and in some cases a description of only one of the duplicate parts will be given. 5 is a pivot carried by the yoke 1, and i as the yoke 1 swings about its hinge '2 into the positions indicated, the'pivot 5 travels in the segment of an arc of a circle described about 2 as a center. 6 is an arm pivoted intermediate of its length to the pivot 5. Two such arms are shown and at their front ends they I are provided with a strike-off bar 7. Fixed in respect to the frame of the machine is a fulcrum 8 shown as arranged in rear of the cen: ter line of the yoke when in vertical position and disposed between the hinge 2- and the path of travel of the pivot 5 Two such fulcrums 8 are shown and between each of them and the end of one of the bars 6 is interposed a link 9 shorter than the distance between the hinge 2 and the pivot 5. As shown the links 9 are adjustable in length by means of the screw and nut connection 10, and they are curved to clear the flask or some of its pro: visions.

The mode of operation may be described as follows:

In the position indicated by dotted lines in Fig. 2 the strike-off bar 7 is back and clear of the flask 4. As the yoke or head 1 is moved from the position indicated in dotted lines to the position indicated by full lines, the pivot 5 travels in the segment of an arc of a circle described about 2 as a center, and the end of the link 9, which isattached to the arm 6, travels in the segment of an arc of a circle described about 8 as a center. The result of these two movements is to cause the edge of the strike-off bar 7 to travel in a substantially straight line, indicated at a by the dash and dot line, until the strike-oft bar 7 99 clears and is in front of the flask l leaving the same free for cooperation with the ramming head or yoke. While the line a is not mathematically straight it is for all practical purposes straightdeparting in thirty inches travel of the-bar 7 in the neighborhood of, for example, a sixteenth of an inch. Of course reference to a sixteenth of an inch variation in a thirty inch travel of the bar 7 is descriptive and is'intended to indicate that for all intents and purposes the edge of the strikeoff bar 7 travels in a horizontal straight line.

Flasks differ in size or depth and for this purpose the arm 6 is provided with more than one pivot hole as indicated at 11 and 12 for the pivot 5 fixed on the yoke, and the arm 6 and the link 9 are each provided with more than one pivot hole as indicated at 13 and 1st for the floating pin 15 by which they are pivotally connected.

It will be obvious to those skilled in the art to which my invention relates that modifications may be made in details of construction and arrangement and matters of mere form without departing from the spirit of the invention which is not limited to such matters or otherwise than the prior art and the appended claims may require.

I claim:

1. Strike-off mechanism for molding machines having a hinged ramming yoke swingable over and back of a flask, a pivot on the yoke adapted to traverse a segment of an arc of a circle described about the hinge of the yoke as a center, arms pivoted intermediate of their ends to said pivot, a strike-off bar can ried at the front ends of the arms, a fulcrum fixed in respect to the fixed frame of the machine and located back of the center line of the yoke in vertical position and between the hinge of the yoke and the path of the pivot, and links pivoted to said fixed fulcrum and to. the rear end of the arms and of less length than the distance between the pivot and the hinge ofthe yoke.

2. Strike-off mechanism for molding machines comprising a pivot, means for causing the pivot to travel in the segment of an arc of a circle to positions above and back of the flask, a fulcrum fixed in respect to the fixed frame of the molding machine and arranged eccentrically with respect to the center about which said are is described, arms pivotally mounted between their ends upon said travel ing pivot, a strike-off bar at one end of said arms, and links pivoted to said fixed fulcrum and to the other end of said arms and adapt-. ed in cooperation with the travel of said piv- 0t to cause the edge of the strike-off bar to move in a substantially straight line across the top of the flask.

3. Strike-off mechanism for molding machines comprising a fixed frame, a yoke hinged to the frame and swingable into vertical position over a flask and into inclined position back of the flask, arms pivoted intermediate of their lengths to the yoke and having at one of their ends a bar adapted to strike sand off the flask, a fulcrum fixed in respect to the fixed frame of the machine and arranged eccentrically in respect to the hinge of the yoke, and links interposed between the fixed fulcrum and the other ends of said arms.

JOHN T. RAMSDEN.

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